An overloaded breaker will lead to a tripped breaker, which is not happening (removing and replacing the charge handle fixes it).
Undersized wire will lead to excessive voltage drop at the vehicle (viewable on the charging screen) and cause the car to reduce the charging current.
The wall unit is not a charger, it is a connector with a 20 mA GFCI and some brains to run a contactor and report the allowable charge current to the vehicle's internal charger.
Problem: Charging is interrupted and the unit displays a red light, pressing reset does not fix it, cycling the breaker or the connector does correct the issue.
@jlghertner, when you say pressing the reset button does nothing, what exactly are you doing?
From the manual (assuming GEN 2):
https://www.tesla.com/sites/default...nstallation_manual_80A_en_US.pdf?201612081439
If a fault causes a RED error light to illuminate or flash and the fault condition is corrected, you use RESET the Wall Connector to resume normal operation. There are two ways to REST the Wall Connector:
•Press the RESET button for two to three seconds until the top lights changes from RED to GREEN. This clears the fault message but does not reboot the Wall Connector.
•In a rare situation, you might need to force the Wall Connector to reboot without recycling the input power. Hold the RESET button for five seconds. When the top light changes from RED to GREEN, release the RESET button. The top light should continue to illuminate GREEN. If the light returns to flashing RED, the fault state has not been corrected.
If all you are getting is a solid red light, the causes can be:
Wall Connector hardware failure.Possible failures include the following:
•Contactor failed
•Self test failed in CCID circuitry
•Other possible hardware failures might be MCU, 3V3output, or the thermal sensor.
And the action recommended is to contact Tesla.
Given that it fails after operating for a while, the contactor would be my suspect. Edit: it could be thermal also.